Understand How Amplifier Noise Contributes to Total Noise in ADC Signal Chains

A forum for the exchange of circuits, systems, and software for real-world signal processing ADI's Engineering University program provides an excellent resource for learning about analog circuitry. The textbook, video lectures, and labs teach analog theory to a high standard, seeding student curiosity; the virtual classroom facilitates international communication, question posing, and remote assistance; and the hardware design platforms inspire students to innovate. The consumer market has adopted High-Definition Multimedia Interface (HDMI) technology in TVs, projectors, and other multimedia devices. This article shows how advanced silicon solutions and smartly implemented software can facilitate HDMI-to-VGA and VGA-to-HDMI converters, which provide engineers familiar with video applications with easy transitions between analog video and digital video. Broadcast radio is becoming increasingly digital, providing listeners with clearer reception, larger coverage area, higher quality sound, additional content, and increased flexibility in accessing and listening to program material. Using the same bandwidth as analog radio, these improvements could be delivered only by digitizing the content, compressing it, and then broadcasting it digitally. Simulation models for amplifiers are typically implemented with resistors, capacitors, transistors, diodes, dependent and independent sources, and other components—or as s-domain transfer functions. This article presents a method that models amplifiers as second-order analog filters, providing much faster time-domain simulations, especially for higher bandwidth amplifiers. With their long life and low energy consumption, LEDs promise to change the lighting industry, but a key limiter to rapid adoption is the cost of the LEDs themselves. In well-designed systems, LEDs can reliably produce many more lumens per dollar of product cost, so to reduce the total luminaire cost we can drive the LEDs at a much higher current than that at which the device is specified. ADCs provide optimal performance when the analog inputs are driven to the rated full-scale input voltage, but the maximum available signal often differs from the specified voltage and may need to be adjusted. A useful device for handling this requirement is a variable-gain amplifier (VGA). Understanding how the VGA affects the ADC's performance will help in optimizing performance of the entire signal chain. On February 1, 2013, Dan Sheingold retired from Analog Devices after 44 years as Editor of Analog Dialogue. He won't be leaving the family, though. Dan will assume the mantle of Editor Emeritus, ensuring that he'll continue to be part of the dialogue. Throughout the 47-year history of Analog Dialogue, only three people have served as Editor: …